ISTANBUL, Turkey (AP) – Turkey warned Thursday that U.S. objections will not stop its troops from crossing into Iraq to pursue Kurdish separatists, while a steady stream of U.S.-made Turkish fighter jets roared across the skies along the border.

High-level Iraqi officials arrived in Turkey as part of frantic efforts to persuade the government not to attack Kurdish guerrilla bases in northern Iraq, and the U.S. ambassador to Iraq sent American diplomats to join the delegation.

Turkey’s leaders have been demanding that U.S. and Iraqi authorities stop Turkish Kurd rebels from staging attacks across the frontier, threatening to send in a large-scale offensive if nothing is done soon.

Turkey still seems willing to refrain from a big attack until at least early next month, when it is scheduled to host foreign ministers to discuss Iraq. Prime Minister Recep Tayyip Erdogan is expected to go to Washington afterward for talks with President Bush.

Turkish artillery has been periodically firing across the border, and Turkish television showed video of smoke rising from three villages in northern Iraq that were purportedly hit by shells Thursday.

Dogan news agency, which provided the footage, said there were no casualties because villagers had fled their homes. It did not cite a source. The agency identified one of the villages as Hezil, three miles from the border with Turkey’s Hakkari province.

The army, meanwhile, reported a clash with rebels earlier in the week. It said a “group of terrorists” was spotted preparing an attack near a military outpost in Semdinli province close to Iraq on Tuesday and troops opened fire with tank cannon, artillery and other heavy weapons.

The report on the military’s Web site also increased the official number for rebels killed since Sunday to at least 64.

The rebel Kurdistan Workers’ Party, or PKK, denied suffering any casualties and called the military statement a “lie,” the pro-Kurdish Firat news agency said.

U.S. officials are urging Turkey not to launch an incursion that could destabilize Iraq’s autonomous Kurdish north, the country’s most stable region.

But Erdogan said the U.S. desire to protect the north would not hinder Turkey’s fight against PKK guerrillas. The rebels use mountain bases in Iraq to rest, train and get supplies in relative safety before returning to Turkey to attack government forces in the heavily Kurdish southeast.

The Bush administration “might wish that we do not carry out a cross-border offensive, but we make the decision on what we have to do,” Erdogan said during a visit to Romania. “We have taken necessary steps in this struggle so far, and now we are forced to take this step and we will take it.”

He said the U.S. should repay Turkish assistance for the invasion of Afghanistan in late 2001 by supporting Turkey’s struggle against the Kurdish rebels, who have demanded autonomy and more democratic rights for Kurds in southeastern Turkey.

Erdogan’s government is facing growing pressure in his streets to move against the rebels, who have stepped up violence in recent weeks.

Tens of thousands of Turks have joined in demonstrations or attended funerals for slain troops this week to demand tough action after a dozen soldiers were killed and eight went missing in a rebel ambush Sunday. The Kurdish rebels say they captured the eight.

“We observe that Israel went into Lebanon to save two of its soldiers,” student Haluk Soysal told AP Television News at an Istanbul protest, referring to the Israel-Hezbollah war a year ago. “But here in Turkey we have eight soldiers held hostage by the PKK, and still we have done nothing.”

APTN cameramen reported several batches of Turkish F-16 fighters flying out of the air base at Diyarbakir and two F-4s flying low along the frontier Thursday, a day after Turkish warplanes reportedly pounded rebel positions on the Turkish side of the border.

More than 10 attack helicopters flew over Hakkari province as government-paid village guards in camouflage, wielding AK-47 asault rifles, patrolled below on roads leading to the border.

“We are totally determined to take all the necessary steps to end this threat,” President Abdullah Gul said in Ankara before the arrival of an Iraqi delegation that included Defense Minister Abdul-Qader al-Obeidi.

Turkey is “expecting them to come with concrete proposals – otherwise, the visit will have no meaning,” Foreign Minister Ali Babacan said.

Yassin Majid, an adviser to Iraqi Prime Minister Nouri al-Maliki, said: “The political choice will be the first solution to solve the crisis. The Iraqi government insists on dialogue and cooperation to solve the crisis.”

Iraq has promised to shut down offices of the PKK. But Turkey wants Iraqi and U.S. forces to destroy the main rebel bases in northern Iraq and extradite PKK leaders to Turkey.

Erdogan’s government warns of a major military offensive as well as economic measures against northern Iraq if its demands are not met. The autonomous Kurdish administration in Iraq’s landlocked north relies heavily on Turkish investment and fuel imports.

On a visit to Damascus, Syria, the speaker of Iraq’s parliament warned the Turks that his government would cut off the flow of oil to Turkey from northern Iraq if Ankara imposes economic sanctions.

“Iraq is a rich country, and if there are economic pressures, we will cut off the Ceyhan pipeline,” Mahmoud al-Mashhadani told reporters, referring to two pipelines that carry oil from northern Iraq to Turkey’s Ceyhan oil terminal on the Mediterranean.

The Iraqi parliament does not have authority to suspend oil contracts, however, although lawmakers could pressure the government to punish Turkey.

In Baghdad, U.S. Ambassador Ryan Crocker said Iraqi forces should do all they can to stop the resupply of PKK insurgents sheltering in northern Iraq. He also called for Iraq’s government to establish a PKK “leaders look-out list.”

“Folks heading up that way need to be stopped, people coming down need to be picked up – to do everything possible to interdict resupply,” Crocker told reporters.

But he added that he was not recommending Iraqi military action against the PKK.

Crocker did not say which members of his embassy staff were sent to Ankara with the Iraqi delegation. He said only that they would join what he called talks to defuse the crisis.

Turkish troops have killed hundreds of Kurdish rebels since Jan. 1, the state-run Anatolia news agency said, citing military sources. It did not say how many Turkish soldiers have died, but about 30 soldiers have been killed this month alone.

AP-ES-10-25-07 1758EDT